I'm running a "bi lingual" phone. OS language is set to English (because I like my computing to be in English) and because of locality I also added German to the voice recognition.

Sometimes Google thinks I'm speaking German when really I'm speaking English and vice versa (especially searching for English named products with a German phrase).

It can get really annoying sometimes. But I guess it's mostly my fault for falling out of the default modus operandi. :)